Fix libtoxav link error.

.travis.yml

@@ -34,7 +34,7 @@ before_script:
   #installing vpx
   - git clone http://git.chromium.org/webm/libvpx.git > /dev/null
   - cd libvpx
-  - ./configure > /dev/null
+  - ./configure --enable-shared > /dev/null
   - make -j3 >/dev/null
   - sudo make install > /dev/null
   - cd ..

configure.ac

@@ -487,7 +487,7 @@ fi
 if test "x$BUILD_AV" = "xyes"; then
     # toxcore lib needs an global?
     # So far this works okay
-    AV_LIBS="$OPUS_LIBS $VPX_LIBS -ltoxcore"
+    AV_LIBS="$OPUS_LIBS $VPX_LIBS"
     AC_SUBST(AV_LIBS)
 
     AV_CFLAGS="$OPUS_CFLAGS $VPX_CFLAGS"

toxav/Makefile.inc

@@ -26,7 +26,8 @@ libtoxav_la_LDFLAGS = $(TOXAV_LT_LDFLAGS) \
                       $(NACL_LDFLAGS) \
                       $(EXTRA_LT_LDFLAGS)
 
-libtoxav_la_LIBS =    $(NACL_LIBS) \
+libtoxav_la_LIBADD =  libtoxcore.la \
+                      $(NACL_LIBS) \
                       $(PTHREAD_LIBS) \
                       $(AV_LIBS)